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排序方式: 共有735条查询结果,搜索用时 46 毫秒
151.
Roberto Marci Maddalena Mallozzi Luisa Di Benedetto Mauro Schimberni Stefano Mossa Ilaria Soave Stefano Palomba Donatella Caserta 《Reproductive biology and endocrinology : RB&E》2018,16(1):112
Hundreds of thousands of young women are diagnosed with cancer each year, and due to recent advances in screening programs, diagnostic methods and treatment options, survival rates have significantly improved. Radiation therapy plays an important role in cancer treatment and in some cases it constitutes the first therapy proposed to the patient. However, ionizing radiations have a gonadotoxic action with long-term effects that include ovarian insufficiency, pubertal arrest and subsequent infertility. Cranial irradiation may lead to disruption of the hypothalamic-pituitary-gonadal axis, with consequent dysregulation of the normal hormonal secretion. The uterus might be damaged by radiotherapy, as well. In fact, exposure to radiation during childhood leads to altered uterine vascularization, decreased uterine volume and elasticity, myometrial fibrosis and necrosis, endometrial atrophy and insufficiency. As radiations have a relevant impact on reproductive potential, fertility preservation procedures should be carried out before and/or during anticancer treatments. Fertility preservation strategies have been employed for some years now and have recently been diversified thanks to advances in reproductive biology. Aim of this paper is to give an overview of the various effects of radiotherapy on female reproductive function and to describe the current fertility preservation options. 相似文献
152.
A successful aging could be gained by life satisfaction, social functioning, or psychological resources and, definitely, by increasing resistance to diverse age‐related pathologies. Nowadays, cancer can be considered an age‐related disease since the incidence of most cancers increases with age, rising more rapidly beginning in midlife. Although adults with extended longevity are less likely to develop cancer, it is now emerging that aging and cancer share common molecular links, and thus targeting these mechanisms may be suitable to treat multiple disorders, for the prolonging of healthy aging. At present, one of the cornerstones of antiaging is hormone‐replacement therapy to treat diseases associated with a state of age‐related sex‐hormone deficiency in women and men; however, many studies question the relationship of hormone replacement to cancer recurrence. Here, we discuss signaling and metabolic molecular crossroad linking aging and cancer. This is useful to argue about the current knowledge of prolongevity and druggable targets and to motivate specific intervention strategies that could modify practices of the aging population, activating multiple longevity pathways but keeping track of cancer pathways, thereby potentially preserving health status. 相似文献
153.
Alessandro Agostini Jens Niklas Tim Schulte Marilena Di Valentin Marco Bortolus Eckhard Hofmann Wolfgang Lubitz Donatella Carbonera 《BBA》2018,1859(8):612-618
The peridinin–chlorophyll-a protein (PCP) is a water-soluble light harvesting protein of the dinoflagellate Amphidinium carterae, employing peridinin (Per) as the main carotenoid to fulfil light harvesting and photo-protective functions. Per molecules bound to the protein experience specific molecular surroundings which lead to different electronic and spectral properties. In the refolded N89?L variant PCP (N89?L-RFPCP) a significant part of the intensity on the long wavelength side of the absorption spectrum is shifted to shorter wavelengths due to a significant change in the Per-614 site energy. Since Per-614 has been shown to be the main chlorophyll (Chl) triplet quencher in the protein, and the relative geometry of pigments is not affected by the mutation as verified by X-ray crystallography, this variant is ideally suited to study the dependence of the triplet-triplet energy transfer (TTET) mechanism on the pigment site energy. By using a combination of Optically Detected Magnetic Resonance (ODMR), pulse Electron Paramagnetic Resonance (EPR) and Electron Nuclear DOuble Resonance (ENDOR) we found that PCP maintains the efficient Per-614-to-Chl-a TTET despite the change of Per-614 local energy. This shows the robustness of the photoprotective site, which is very important for the protection of the system. 相似文献
154.
Not only trees: Grasses determine African tropical biome distributions via water limitation and fire 下载免费PDF全文
Donatella D'Onofrio Jost von Hardenberg Mara Baudena 《Global Ecology and Biogeography》2018,27(6):714-725
Aim
Although much tropical ecology generally focuses on trees, grasses are fundamental for characterizing the extensive tropical grassy biomes (TGBs) and, together with the tree functional types, for determining the contrasting functional patterns of TGBs and tropical forests (TFs). To study the factors that determine African biome distribution and the transitions between them, we performed the first continental analysis to include grass and tree functional types.Location
Sub‐Saharan Africa.Time period
2000–2010.Major taxa studied
Savanna and forest trees and C4 grasses.Methods
We combined remote‐sensing data with a land cover map, using tree functional types to identify TGBs and TFs. We analysed the relationships of grass and tree cover with fire interval, rainfall annual average and seasonality.Results
In TGBs experiencing < 630 mm annual rainfall, grass growth was water limited. Grass cover and fire recurrence were strongly and directly related over the entire subcontinent. Some TGBs and TFs with annual rainfall > 1,200 mm had the same rainfall seasonality but displayed strongly different fire regimes.Main conclusions
Water limitation to grass growth was fundamental in the driest TGBs, acting alongside the well‐known limitation to tree growth. Marked differences in fire regimes across all biomes indicated that fire was especially relevant for maintaining mesic and humid TGBs. At high rainfall, our results support the hypothesis of TGBs and TFs being alternative stable states maintained by a vegetation–fire feedback for similar climatic conditions. 相似文献155.
Paulina Corral Fortunato Palma Esposito Pietro Tedesco Angela Falco Emiliana Tortorella Luciana Tartaglione Carmen Festa Maria Valeria D’Auria Giorgio Gnavi Giovanna Cristina Varese Donatella de Pascale 《Marine biotechnology (New York, N.Y.)》2018,20(4):502-511
The exploration of poorly studied areas of Earth can highly increase the possibility to discover novel bioactive compounds. In this study, the cultivable fraction of fungi and bacteria from Barents Sea sediments has been studied to mine new bioactive molecules with antibacterial activity against a panel of human pathogens. We isolated diverse strains of psychrophilic and halophilic bacteria and fungi from a collection of nine samples from sea sediment. Following a full bioassay-guided approach, we isolated a new promising polyextremophilic marine fungus strain 8Na, identified as Aspergillus protuberus MUT 3638, possessing the potential to produce antimicrobial agents. This fungus, isolated from cold seawater, was able to grow in a wide range of salinity, pH and temperatures. The growth conditions were optimised and scaled to fermentation, and its produced extract was subjected to chemical analysis. The active component was identified as bisvertinolone, a member of sorbicillonoid family that was found to display significant activity against Staphylococcus aureus with a minimum inhibitory concentration (MIC) of 30 μg/mL. 相似文献
156.
Donatella Verbanac Cedomila Milin Robert Domitrovic Jasminka Giacometti Radojka Pantovic Zlatko Ciganj 《Biological trace element research》1997,57(1):91-96
The most commonly encountered difficulties for the quantitative measurement of zinc in biological samples are the limited
sample amount, total and effective digestion of connective and fatty residues, and low zinc concentrations. These problems
often lead to the determination of lower zinc values than actually present, so that the sample preparation, digestion, and
analytical procedure deserve careful attention.
In this short communication, a new method for microwave tissue disintegration is described. The authors have obtained consistent
and reproducible results with tissue samples of 0.5 g or less. 相似文献
157.
158.
159.
The effect of maternal exposure to endocrine disrupting chemicals on fetal and neonatal development: A review on the major concerns 下载免费PDF全文
Maddalena Mallozzi Giulia Bordi Chiara Garo Donatella Caserta 《Birth defects research. Part C, Embryo today : reviews》2016,108(3):224-242
There is a widespread exposure of general population, including pregnant women and developing fetuses, to the endocrine disrupting chemicals (EDCs). These chemicals have been reported to be present in urine, blood serum, breast milk, and amniotic fluid. Endocrine disruptions induced by environmental toxicants have placed a heavy burden on society, since environmental exposures during critical periods of development can permanently reprogram normal physiological responses, thereby increasing susceptibility to disease later in life—a process known as developmental reprogramming. During development, organogenesis and tissue differentiation occur through a continuous series of tightly‐regulated and precisely‐timed molecular, biochemical, and cellular events. Humans may encounter EDCs daily and during all stages of life, from conception and fetal development through adulthood and senescence. Nevertheless, prenatal and early postnatal windows are the most critical for proper development, due to rapid changes in system growth. Although there are still gaps in our knowledge, currently available data support the urgent need for health and environmental policies aimed at protecting the public and, in particular, the developing fetus and women of reproductive age. Birth Defects Research (Part C) 108:224–242, 2016. © 2016 Wiley Periodicals, Inc. 相似文献
160.
Rapid leaf development drives the seasonal pattern of volatile organic compound (VOC) fluxes in a ‘coppiced’ bioenergy poplar plantation 下载免费PDF全文
Federico Brilli Beniamino Gioli Silvano Fares Zenone Terenzio Donatella Zona Bert Gielen Francesco Loreto Ivan A. Janssens Reinhart Ceulemans 《Plant, cell & environment》2016,39(3):539-555
Leaves of fast‐growing, woody bioenergy crops often emit volatile organic compounds (VOC). Some reactive VOC (especially isoprene) play a key role in climate forcing and may negatively affect local air quality. We monitored the seasonal exchange of VOC using the eddy covariance technique in a ‘coppiced’ poplar plantation. The complex interactions of VOC fluxes with climatic and physiological variables were also explored by using an artificial neural network (Self Organizing Map). Isoprene and methanol were the most abundant VOC emitted by the plantation. Rapid development of the canopy (and thus of the leaf area index, LAI) was associated with high methanol emissions and high rates of gross primary production (GPP) since the beginning of the growing season, while the onset of isoprene emission was delayed. The highest emissions of isoprene, and of isoprene photo‐oxidation products (Methyl Vinyl Ketone and Methacrolein, iox), occurred on the hottest and sunniest days, when GPP and evapotranspiration were highest, and formaldehyde was significantly deposited. Canopy senescence enhanced the exchange of oxygenated VOC. The accuracy of methanol and isoprene emission simulations with the Model of Emissions of Gases and Aerosols from Nature increased by applying a function to modify their basal emission factors, accounting for seasonality of GPP or LAI. 相似文献